In recent years, high-intensity and high-output light emitting elements and miniature light emitting devices have been developed, and used in various fields. These light emitting devices are made full use of the characteristics such as small size, low power consumption and low weight, and for example, have been utilized for application as a light source in a liquid-crystal backlight and mobile telephones, a light source for various types of meters, and various types of scanning sensors. Various techniques have been designed to realize higher intensity illumination and reduce size (for example, JP 2011-249807A and JP2008-153610A, etc.).
As an example, a metal member used as a lead frame or a wire used in wire bonding which are composed of silver or a silver alloy have been used as a metal member or a wire. In this manner, a method has been proposed to suppress absorption of light by the light emitting element, and efficiently reflect and extract light.
In order to prevent sulfuration of the silver or the silver alloy, various proposals have been made in relation to a resin and a package material to seal the light emitting element (for example, JP 2011-256326A and JP2011-178983A etc.).
However, in general, when silver and a silver alloy are used as a material for a lead frame and a wire or the like, sulfuration of such members occurs and therefore causes absorption of the light from the light emitting element, with the result that there is the problem that efficient reflection of light is hindered.
Moreover even when a resin having a composition that enables highly effective suppression of sulfuration of silver is used, such sulfuration starts as a result of air or moisture or the like that enters into the tiny gaps between the resin and the resin, or between the resin and the lead frame, and expands, with the result that efficient sulfuration suppression is not realized.